Trying something with code from Geodesic Maths for OpenScad - ThingiversePreview is fine.Trying to render coughs out Rendering Polygon Mesh using CGAL...ERROR: The given mesh is not closed! Unable to convert to CGAL_Nef_Polyhedron.If I take out the cylinder, no error.I even extracted code from maths_geodesic.scad so I might isolate any problem, but no joy.OpenSCAD 2021.01running on a MacBookPro running Big Sur (macOS 11.6)# ------------------- BEGIN CODE -------------------//include <maths_geodesic.scad>//--------------------------------------------//WITHOUT  <maths_geodesic.scad>Cepsilon = 0.00000001;function sph(long, lat, rad=1) = [long, lat, rad];// Clean: Correctedfunction clean(n) = (n < 0) ? ((n < -Cepsilon) ? n : 0) : (n < Cepsilon) ? 0 : n;// Convert spherical to cartesianfunction sph_to_cart(s) = [clean(s[2]*sin(s[1])*cos(s[0])), clean(s[2]*sin(s[1])*sin(s[0])),clean(s[2]*cos(s[1]))];//--------------------------------------------module icosahedron ( radius = 1 ) {  foo = atan ( 0.500 ) ;   polyhedron(    points = [      sph_to_cart ( sph(   0,   0,       rad = radius ) ) , //  0      sph_to_cart ( sph(  36,  90 - foo, rad = radius ) ) , //  1      sph_to_cart ( sph( 108,  90 - foo, rad = radius ) ) , //  2      sph_to_cart ( sph( 180,  90 - foo, rad = radius ) ) , //  3      sph_to_cart ( sph( 252,  90 - foo, rad = radius ) ) , //  4      sph_to_cart ( sph( 324,  90 - foo, rad = radius ) ) , //  5      sph_to_cart ( sph(  72,  90 + foo, rad = radius ) ) , //  6      sph_to_cart ( sph( 144,  90 + foo, rad = radius ) ) , //  7      sph_to_cart ( sph( 216,  90 + foo, rad = radius ) ) , //  8      sph_to_cart ( sph( 288,  90 + foo, rad = radius ) ) , //  9      sph_to_cart ( sph( 360,  90 + foo, rad = radius ) ) , // 10      sph_to_cart ( sph(   0, 180,       rad = radius ) )   // 11    ],    faces = [      [ 0, 1, 2],      [ 0, 2, 3 ],      [ 0, 3, 4 ],      [ 0, 4, 5 ],      [ 0, 5, 1 ],      [ 1, 6, 10 ],      [ 2, 6, 1 ],      [ 2, 6, 7 ],      [ 2, 3, 7 ],      [ 3, 7, 8 ],      [ 3, 8, 4 ],      [ 4, 8, 9 ],      [ 4, 9, 5 ],      [ 5, 9, 10 ],      [ 5,10, 1 ],      [ 11, 6, 7 ],      [ 11, 7, 8 ],      [ 11, 8, 9 ],      [ 11, 9, 10 ],      [ 11, 10, 6 ]    ],    convexity = 1  ) ;}icosahedron ( ) ;cylinder ( h = 0.01, r = 1, $fn = 25 ) ;# ------------------- END CODE -------------------Dan White | d_e_white@icloud.com ------------------------------------------------ “Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us.” (Bill Waterson: Calvin & Hobbes)